Not so sure. I think there are two reasons Jose is no longer effective. These are:
1) He is tactically inflexible and his style isn't suited to the modern game.
2) His man management style is that of a hard taskmaster.
Your point touches on the 2nd, however I think a big reason why players now aren't good with hard taskmasters is due to them having been pampered from before they were teenagers, given vast sums of money in their teens and having massive social media followings and everything that goes with that narcissism/vanity etc.
Players from his first Chelsea team, Porto and Inter still had to clean the boots of older pros and had YTS type contracts until they hit 17/18 so where used to having to graft to an extent. Today's footballers are far too precocious imo.
That said, I think, tactically, he has been done for the best part of 6-7 years now.